Dear Sir,
After reading your job post, I deemed myself as one of the best contenders for this position.
Sir,
As a proactive and interested writer, I think I can perform your given task with my utmost sincerity and great dedication.
Sir,
I'll complete your job within your given deadline and obviously without any mistakes. Hope to work with you, Sir.
Sir,
As my profile shows you that I'm very new in this arena but after completion of my job I hope you will feel satisfied, as I'm working in this line for long 2 and half years. I used to work under one of my native seniors for a long time. Then I decided to perform on my own as I was deprived.
Sir,
Thanks for your time and consideration.
With Profound Regards
Sakib